The URL Interface provides a direct access to the Washington Department of Revenue’s address based rate lookup technology platform. Using the URL interface we provide, you can access sales and use tax rate data using address or ZIP + 4 code information and tie the data into your shopping cart checkout process or accounting system in real time. The following information is the technical specifications to access the URL interface.

1. The rate lookup URL is designed to return the current sales tax rates for an address. It is designed for use by XMLHttpRequest, Msxml2.XMLHTTP, libcurl, wget, HttpRequest, or similar HTTP protocol client. Requests can be made for ether XML or plain text responses.

2. The URL is formated as follows.

http://<servername>/AddressRates.aspx?output=<format>&addr=<address>&city=<city>&zip=<zip>
Where
<servername> ==> Host name where the service is running.
<format> ==> Either "xml" or "text".
<address> ==> The street address.
<city> ==> The city name
<zip> ==> The 5 or 9 digit ZIP code.
Examples
http://dor.wa.gov/AddressRates.aspx?output=xml&addr=6500 Linderson way&city=&zip=98501
http://dor.wa.gov/AddressRates.aspx?output=text&addr=6500 Linderson way&city=&zip=985011001
http://dor.wa.gov/AddressRates.aspx?output=xml&addr=6500 Linderson way&city=&zip=98501-1001

3. HTTP Status Codes

The service will normally return a HTTP status code of 200 OK. On internal error, it will return a 500 internal server error.

4. Result Codes

A result code will be returned for both XML and text response formats. The codes are defined as:

0: The address was found.
1: The address was not found, but the ZIP+4 was located.
2: Neither the address or ZIP+4 was found, but the 5-digit ZIP was located.
3: The address, ZIP+4, and ZIP could not be found.
4: Invalid arguements.
5: Internal error.

5. Plain Text Response Format

If the format requested is "text", a simple text string will be returned with the following format.

LocationCode=<location code> Rate=<rate> ResultCode=<result code>
Where
<location code> ==> The four digit DOR location code.
<rate> ==> The total state and local tax rate.
<result code> ==> The result code described above.
Example
LocationCode=3406 Rate=0.084 ResultCode=0